Heteroleptic light-emitting complexes

Abstract

Heteroleptic light emitting complexes having the general formula M(L 1 ) n (L 2 ) m , wherein a) L 1 has the formula E1-E2, wherein E1 is a 6-membered heteroaryl ring bound to the metal atom M by a dative bond and containing at least one donor hetero atom and E2 is bound to the metal atom by covalent or dative bonds and is selected from the group consisting of substituted or unsubstituted C 5 -C 30 aryl and substituted or un-substituted C 2 -C 30 heteroaryl groups, b) ligand L 2 is selected from the group consisting of 1-(2,6 disubstituted phenyl)-2-phenyl-1 H-imidazole ligands or 5-(2,6 disubstituted phenyl)-1-phenyl-1 H-pyrazole ligands, and c) M is a non-radioactive transition metal with an atomic number of at least 40 and the sum of m and n is equal to half of the bond valency of metal M.

The invention claimed is: 
     
       1. A heteroleptic light emitting complex having the general formula M(L 1 ) m (L 2 ) n  wherein
 a) L 1  is selected from substituted or unsubstituted 2-phenylquinoline and substituted or unsubstituted 1-phenylisoquinoline ligands of formulae (3) and (4) 
 
       
         
           
           
               
               
           
         
         wherein R 8  to R 13 , which may be the same or different at each occurrence, are selected from the group consisting of H, halogen, NO 2 , CN, N(R 6 ) 2 , B(OR 6 ) 2 , COOH, C(O)R 6 , CO 2 R 6 , CON(R 6 ) 2 , OR 6 , SR 6 , SO 3 H, S(═O)R 6 , S(═O) 2 R 6 , P(R 6 ) 2 , P(═O)(R 6 ) 2 , Si(R 6 ) 3 , alkyl, alkenyl, alkynyl, aryl, substituted aryl, alkylaryl, heteroaryl, substituted heteroaryl and heterocyclic groups, with R 6 , which may be the same or different, being selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl, substituted aryl, alkylaryl, halogen, heteroaryl, substituted heteroaryl and heterocyclic groups, 
         p, u and v, independent of one another, represent an integer of from 0 to 4, t represents an integer from 0 to 3 and s and w, independent of one another represent an integer of from 0 to 2, 
         b) ligand L 2  is selected from the group consisting of 1-(2,6 disubstituted phenyl)-2-phenyl-1H-imidazole ligands or 5-(2,6 disubstituted phenyl)-1-phenyl-1H-pyrazole ligands of formulae 1 or 2 
       
       
         
           
           
               
               
           
         
         wherein 
         R 1  and R 2 , which may be the same or different, each represent a C 1  to C 20  alkyl or haloalkyl group, a cycloalkyl group, a C 5  to C 30  aryl group or a C 2  to C 30  heteroaryl group, said cycloalkyl, aryl and heteroaryl groups being un-substituted or substituted by substituents selected from the group consisting of halogen, alkyl, alkoxy, amino, cyano, alkenyl, alkynyl, arylalkyl, aryl and heteroaryl groups; and 
         R 3  is selected from the group consisting of H, halogen, NO 2 , CN, N(R 4 ) 2 , B(OR 4 ) 2 , COOH, C(O)R 4 , CO 2 R 4 , CON(R 4 ) 2 , OR 4 , SR 4 , SO 3 H, S(═O)R 4 , S(═O) 2 R 4 , P(R 4 ) 2 , P(═O)(R 4 ) 2 , Si(R 4 ) 3 , alkyl, cycloalkyl, haloalkyl, alkoxy,alkenyl, alkynyl, aryl, alkylaryl, heteroaryl, substituted heteroaryl and heterocyclic groups, with the proviso that R 3  is not aryl if ligand L 2  is represented by formula 1, 
         R 4  which may be the same or different, are selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl, substituted aryl, alkylaryl, halogen, heteroaryl, substituted heteroaryl and heterocyclic groups, 
         R and R′, independently of one another, are selected from the group consisting of H, halogen, NO 2 , CN, N(R 5 ) 2 , B(OR 5 ) 2 , COOH, C(O)R 5 , CO 2 R 5 , CON(R 5 ) 2 , OR 5 , SR 5 , SO 3 H, S(═O)R 5 , S(═O) 2 R 5 , P(R 5 ) 2 , P(═O)(R 5 ) 2 , Si(R 5 ) 3 , alkyl, alkenyl, alkynyl, aryl, substituted aryl, alkylaryl, heteroaryl, substituted heteroaryl and heterocyclic groups, 
         R 5  which may be the same or different, are selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl, substituted aryl, alkylaryl, halogen, heteroaryl, substituted heteroaryl and heterocyclic groups, 
         a is an integer of from 0 to 3 and b is an integer of from 0 to 2, and c is an integer of from 0 to 3, 
         c) M is Ir, m is 2, and n is 1. 
       
     
     
       2. The heteroleptic light emitting complex in accordance with  claim 1 , wherein ligand L 2  is selected from 1-(2,6 disubstituted phenyl)-2-phenyl-1H-imidazole ligands of formula (1) wherein R 3  is H or a C 1  to C 20  alkyl group. 
     
     
       3. The heteroleptic light emitting complex in accordance with  claim 1  wherein ligand L 2  is selected from 5-(2,6 disubstituted phenyl)-1-phenyl-1H-pyrazole ligands of formula (2) wherein R 3  is H or a C 1  to C 20  alkyl group. 
     
     
       4. The heteroleptic light emitting complex in accordance with  claim 1  wherein at least one of R 1  and R 2  is a C 1  to C 20  alkyl group. 
     
     
       5. The heteroleptic light emitting complex in accordance with  claim 4  wherein R 1  and R 2  are independently selected from C 1  to C 8  alkyl groups. 
     
     
       6. The heteroleptic light emitting complex in accordance with  claim 5  wherein R 1  and R 2  are independently selected from methyl and isopropyl. 
     
     
       7. The heteroleptic light emitting complex in accordance with  claim 1  represented by any one of formulae (5) to (8): 
       
         
           
           
               
               
           
         
         wherein R 1  to R 3  have the meanings as defined in  claim 1  and wherein the phenylquinoline and phenylisoquinoline ligands may be substituted or unsubstituted. 
       
     
     
       8. The heteroleptic light emitting complex in accordance with  claim 1  wherein ligand L 1  is a 2-phenylquinoline ligand and ligand L 2  is a ligand of formula (2). 
     
     
       9. The heteroleptic light emitting complex in accordance with  claim 1  wherein the triplet energy level of ligand L 2  is higher than the triplet energy level of ligand L 1 . 
     
     
       10. An emitting layer of an organic light emitting device comprising the heteroleptic light emitting complex according to  claim 1 . 
     
     
       11. An organic light emitting device comprising an emissive layer, said emissive layer comprising a heteroleptic light emitting complex according to  claim 1 . 
     
     
       12. An organic light emitting device comprising an emissive layer, said emissive layer comprising a heteroleptic light emitting complex according to  claim 1  as dopant and a host material represented by general formulae (9) or (10) : 
       
         
           
           
               
               
           
         
         wherein A is a single bond or a divalent residue of biphenyl, triphenyl, 
       
       
         
           
           
               
               
           
         
         in each of which one or more hydrogen atoms attached in the carbon atoms may be replaced by a substituent other than hydrogen, wherein Z is any one selected from N, O, S, and SiR 16 , Y is N—R 16 , O, S, Si(R 16 ) 2 where R 16  is C 1 -C 20  alkyl or C 1 -C 20  aryl, R 14  and R 15  are independently selected from hydrogen or C 1 -C 20  alkyl; 
         X 1  to X 4  are independently selected from substituents other than spirobifluorenyl; 
         1, p and q are integers between 0 to 4; 
         m is an integer between 0 to 3, 
       
       
         
           
           
               
               
           
         
         wherein B 1  and B 2  are independently selected from hydrogen, and a heterocyclic group; 
         r is an integer between 0 to 3; and X 1  to X 4 , m, p, and q are as defined for Formula (9).